One simple issue would be if your object looks like x = {"__proto__": {"foo": "bar"}} now x.foo is "bar" if that's JS code, but undefined if you JSON.parse th

One simple issue would be if your object looks like x = {"__proto__": {"foo": "bar"}} now x.foo is "bar" if that's JS code, but undefined if you JSON.parse that same object definition from a string.